2.11.7. V4L2_SDR_FMT_PCU18BE (‘PC18’)

Planar complex unsigned 18-bit big endian IQ sample

2.11.7.1. Description

This format contains a sequence of complex number samples. Each complex number consist of two parts called In-phase and Quadrature (IQ). Both I and Q are represented as a 18 bit unsigned big endian number stored in 32 bit space. The remaining unused bits within the 32 bit space will be padded with 0. I value starts first and Q value starts at an offset equalling half of the buffer size (i.e.) offset = buffersize/2. Out of the 18 bits, bit 17:2 (16 bit) is data and bit 1:0 (2 bit) can be any value.

Byte Order. Each cell is one byte.

Offset:	Byte B0	Byte B1	Byte B2	Byte B3
start + 0:	I’0[17:10]	I’0[9:2]	I’0[1:0]; B2[5:0]=pad	pad
start + 4:	I’1[17:10]	I’1[9:2]	I’1[1:0]; B2[5:0]=pad	pad
…
start + offset:	Q’0[17:10]	Q’0[9:2]	Q’0[1:0]; B2[5:0]=pad	pad
start + offset + 4:	Q’1[17:10]	Q’1[9:2]	Q’1[1:0]; B2[5:0]=pad	pad